Josh Young, Chuck Cooper and Erin Mackey star in Amazing Grace, the true story of a former slave trader who wrote the hymn beloved across the globe. Composer Christopher Smith (music, lyrics, and book along with Arthur Giron) is not formerly trained — he took some lessons as a kid, but never learned to read or write music well. He sat down with Playbill to share his unconventional, but very effective, collaborative songwriting process.